This invention relates to internal combustion engines and more particularly to an engine with air-assisted direct cylinder fuel injection.
It is known in the art relating to spark-ignited internal combustion engines to provide for the direct injection of fuel into the combustion chambers, normally through the cylinder head of the engine. Air-assisted direct injection fuel systems have been developed for such engines which utilize a combination of solenoid-actuated fuel injectors which inject pressurized fuel into associated air injectors. The air injectors mix pressurized air with the fuel and inject the mixture of air and fuel directly into the engine combustion chambers. The air injectors are mounted in the engine cylinder head and the fuel injectors are mounted at the outer ends of the air injectors. Separate air and fuel rails are provided which respectively supply air to the air injectors and fuel to the fuel injectors. The arrangement is easily modified for application to various engine configurations but involves a large number of components to be mounted along the top of the cylinder head and having external fittings and connections.
The present invention provides an improved arrangement for an air-assisted fuel injection system mounted on an engine. The engine includes an internal air passage acting as an air manifold and preferably disposed in an engine cylinder head or other component defining a portion of an associated combustion chamber. Modified air injectors are provided which fit into stepped boars in the cylinder head and include seals at opposite ends of a central portion of the bore which defines annular air pockets. The air pockets are intersected by the internal air passage or manifold running longitudinally along the length of the cylinder head. The air passage or manifold is provided with pressurized air from an external source which is fed to the air pockets and enters each of the air injectors.
These and other features and advantages of the invention will be more fully understood from the following description of certain specific embodiments of the invention taken together with the accompanying drawings.